1. Field of the Invention
This invention relates, in general, to concrete roads and pavements, and, more particularly, to an improved roadway expansion joint and method for prevention of pavement buckling.
2. Prior Art
Concrete roads are usually constructed of separate, longitudinally aligned molded slabs, each of which is poured in place with the vertical ends of the slab spaced slightly away from the end of a previously poured slab. After the slabs have set, the joints between their ends are sealed with a thermoplastic sealing material, such as asphalt, sufficient space being left between the slabs to accommodate the expansion thereof due to the normally elevated temperatures of summer. However, when temperatures rise to abnormally high levels, the total expansion of a number of slabs exceeds the combined space between their ends with the result that at certain joints the ends of the slabs butt up solidly against each other with such immense force that the ends buckle, often explosively, with spalling and pulverization of the slabs extending in both directions from the joint over several feet. Obviously, driving on a road which has been damaged in this manner is dangerous and satisfactory repairs can only be effected by removing the broken material and pouring fresh concrete, which prolongs the period that a road is impassable due to heat buckling.
Another major problem has been the accumulation of dirt, rocks or other trash in the roadway joint which results in quicker deterioration of the roadways.
All of these problems require immediate attention which results many times in major highways being partially or completely closed during peak traffic times or during weekends.
Many proposed solutions of these problems have been disclosed, such as those seen in the following patents:
______________________________________ U.S. Pat. No. Inventor Issued Title ______________________________________ Des. 261,555 Bowman 10/27/81 Expansion Joint Sealing Strip for Roadway Joints and the Like Des. 261,046 Bowman 09/29/81 Expansion Joint Sealing Strip Assembly for Roadways and the Like Des. 261,045 Bowman 09/29/81 Expansion Joint Sealing Strip for Roadway Joints and the Like Des. 260,684 Bowman 09/08/81 Expansion Joint Sealing Strip for Roadway Joints Des. 260,557 Bowman 09/01/81 Expansion Joint Sealing Strip Assembly for Roadways Joints 3,245,328 Fassbinder 04/12/66 Expansion Joint for Road Covering Structures 3,324,774 Boschi 06/13/67 Expansion Joint for Road Sections 3,273,473 Pare 09/20/66 Road Expansion Joint 3,316,574 Pare 05/02/67 Road Expansion Joint 3,427,935 Boschi 02/18/69 Expansion Joint for Roads and Bridges 3,677,145 Wattlez 07/18/72 Expansion Joint for Road Works 3,720,474 Stog, et al 03/13/73 Expansion Joint 3,826,583 Pare 07/30/74 Leaf Spring Pave- ment Joint Seal 3,851,989 Peach 12/03/74 Expansion Joint for Slabs of Concrete Roadways 3,877,829 Honegger 04/15/75 Roadway Expansion Joint 3,899,261 Mieville 08/12/75 Expansion Joint Batten or Packing of Dilation Joint 3,904,304 Honegger 09/09/75 Expansion Joints for a Roadway 3,972,640 Miller 08/03/76 Highway Joint with Spring Torsion Bar 4,076,440 Bertschmann 02/28/78 Expansion Joint Bridging Device 4,087,191 Brady, et al 05/02/78 Large Motion Expansion Joint 4,279,533 Peterson, et al 07/21/81 Roadway Expansion Joint 1,369,161 Benson, et al 2/22/21 Pavement ______________________________________
However, for a multitude of reasons, such prior art devices have been found not to work or have been impractical.